The Jaysh al-Muhajireen wal-Ansar (The Army of Emigrants and Helpers) was officially formed at the end of March, 2013. It began as three different groups, including the Kataeb al-Muhajireen (The Brigade of Emigrants), the Kataeb al Khattab (The Brigade of Khattab), and the Jaysh Muhammad (Army of Muhammad). The latter two were Syrian groups, while the first consisted of Chechens, Turks, Tajiks, Pakistanis, French, Egyptians, Moroccans, and others. A group of jihadists, including Chechens and Bangladeshis, were arrested in London in October 2012, planning to join the Muhajireen Brigade, and in March, a Swedish jihadist known as Abu Kamal as Swedee was killed while fighting with the Brigade.
The Muhajireen Brigade first became visible in early 2013, led by a veteran Chechen commander known as Abu Omar al Chechen, or Abu Omar al Shishani. While Chechen fighters had been spotted on Syrian battlefields for months, it wasn’t until February that there was any official mention of the Muhajireen Brigade. That was when Abu Omar appeared in a video with 19 other jihadists on Kavkaz Center‘s website.
The Brigade, and the Army after it, have had no official propaganda arm. All information on them and their operations has come second hand, usually from Russian language sites.
The Brigade, while not named as such at the time, assisted the Al Nusra Front in its assault on the Sheikh Suleiman Base in Aleppo in December. There was mention of a “Muhajireen group,” but since “muhajireen” simply means “emigrant,” all it really conveyed was the fact that there were a significant number of foreign jihadists operating in Syria.